1. Field of the Invention
The present invention relates to an encoding method for error correction which is applied to record, for example, an audio PCM signal on a magnetic tape by a rotary head.
2. Description of the Prior Art
There is known a method for performing the error detection or encoding error correction codes in the longitudinal and lateral directions of digital information data arranged like a matrix, respectively. As one method in case of transmitting these codes for every column and decoding them on the reception side, there is considered a method whereby the error detection is performed by a first error detection code for each column, a pointer as a result of this is produced, and the data and pointer of each column are stored in a memory, then the error correction is performed for every row by a second error correction code with reference to this pointer.
Upon this decoding, a block address is added in order to write the data in each column (hereinbelow, referred to as a block) in the memory in accordance with the correct time sequence. However, in the case in which the error detection is performed for every block, there is a problem that if a block address is wrong, it is impossible to detect that the data is written in a wrong address of the memory, so that when the erasure correction using the pointer is performed by the second error correction code, the wrong error correction will have been done.